Trypanosoma caninum n. sp. (Protozoa: Kinetoplastida) isolated from intact skin of a domestic dog ( Canis familiaris) captured in Rio de Janeiro, Brazil.

An unknown Trypanosoma species was isolated from an axenic culture of intact skin from a domestic dog captured in Rio de Janeiro, Brazil, which was co-infected with Leishmania (Viannia) braziliensis. Giemsa-stained smears of cultures grown in different media revealed the presence of epimastigotes, trypomastigotes, spheromastigotes, transitional stages, and dividing forms (epimastigotes or spheromastigotes). The highest frequency of trypomastigotes was observed in RPMI (15.2%) and DMEM (9.2%) media containing 5% FCS, with a mean length of these forms of 43.0 and 36.0 mum, respectively. Molecular analysis by sequential application of PCR assays indicated that this trypanosome differs from Trypanosoma cruzi and T. rangeli when specific primers were applied. On the other hand, a PCR strategy targeted to the D7 domain of 24salpha rDNA, using primers D75/D76, amplified products of about 250 bp in that isolate (stock A-27), different from the amplification products obtained with T. cruzi and T. rangeli. This organism differs from T. cruzi mainly by the size of its trypomastigote forms and kinetoplasts and the absence of infectivity for macrophages and triatomine bugs. It is also morphologically distinct from salivarian trypanosomes reported in Brazil. Isoenzyme analysis at 8 loci demonstrated a very peculiar banding pattern clearly distinct from those of T. rangeli and T. cruzi. We conclude that this isolate is a new Trypanosoma species. The name T. caninum is suggested.

Computerized generation of circadian sensor modal days with continuous glucose monitoring for comparison of various insulin regimens based on insulin glargine in type 1 diabetes.

AIM: Our aims were (1) to design and standardize a statistical approach for data reduction in continuous glucose monitoring, allowing comparison of circadian glycemic patterns in therapeutic subcohorts of patients with type 1 diabetes, and (2) to investigate the applicability of this approach for CGMS assessment in clinical study of basal insulin replacement quality with various timings of basal injections (pre-breakfast, dinner, bedtime) of a new insulin analog. METHODS: Prospective randomized three-arm parallel study with switch over after 6 months for another 3 months of free choice injection time point (options pre-breakfast, pre-dinner and bedtime) of the new insulin analog in 16 type 1 diabetic subjects on functional insulin treatment (FIT: basal, prandial and correctional dosages). CGMS was used at the end of each follow up period of a clinical study. Representative daily profiles were off-line computed as "circadian sensor modal days" for each insulin regimen consisting of consecutive means of hourly glucose values. RESULTS: Although the overall quality of glycemic control (HbAIC) for different regimens did not reach statistical differences, CGMS displayed slightly divergent maximal swings in the course of glycemia (p=0.04-0.08) and allowed--with delineated data reduction procedure--a reliable between treatment comparison. CONCLUSION: Off-line computation of "hourly circadian sensor modal days" for data reduction can be effectively used with CGMS for description of circadian glycemic patterns in type 1 diabetes.

The combined dexamethasone-CRH test before and after repetitive transcranial magnetic stimulation (rTMS) in major depression.

BACKGROUND: Hypothalamic-pituitary-adrenocortical (HPA) dysregulation assessed by the combined dexamethasone corticotropin releasing hormone test (DEX/CRH test) has been demonstrated to normalize after successful antidepressant pharmacotherapy. Here, we investigated whether repetitive transcranial magnetic stimulation (rTMS) also leads to a normalization of HPA system activity in depressed patients. METHODS: Thirty-seven medication free patients suffering from a major depressive episode (DSM-IV) underwent a DEX/CRH test before and after 13 daily sessions of left prefrontal rTMS in an open trial. RESULTS: There was an overshoot of CRH-induced cortisol release that was not affected by rTMS treatment. Postdexamethasone cortisol levels prior to CRH challenge decreased in responders after rTMS treatment, whereas no change of CRH-induced adrenocorticotropic hormone (ACTH) and cortisol release in responders or nonresponders was observed. CONCLUSIONS: The persisting HPA system hyperactivity after rTMS suggests a high risk for relapse and therefore argues for an immediate maintenance therapy in patients responding to this treatment.

Functional and biological test of a 20 channel implantable stimulator in sheep in view of functional electrical stimulation walking for spinal cord injured persons.

A newly developed implantable stimulator with 20 output channels, mainly intended for the stimulation of lower extremities in paraplegics, was implanted in 6 sheep over a time period of 26 weeks. Five epineural electrodes each were used to contact various nerves at different locations to elicit hip and knee extension and flexion and to make carrousel and selective stimulation possible. Different electrode application strategies in view of paraplegic standing and walking were investigated. Additional implanted electrodes allowed M-wave monitoring for selectivity investigations in 3 sheep. Stimulator, electrode leads, and electrodes proved to be reliable. Selective stimulation with electrodes placed on the trunk of the sciatic nerve could be demonstrated but with bad reproducibility. Histological investigation of the tissues surrounding electrodes and leads showed the expected stable foreign body response. Strong hip and knee extension could be gained in all cases while only weak flexion forces could be elicited in most cases. Muscle biopsies showed that daily stimulation for 8 h at threshold level caused an increase in muscle Type I fibers and a decrease in Type IIc fibers. Implants and electrodes fulfill the most important functional and biological criteria for their clinical application for paraplegic walking. The intention to provide selective flexion functions via epineural stimulation could not be demonstrated sufficiently in this animal model.

Internal exposure to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) of Bavarian chimney sweeps.

This study was carried out to evaluate the internal exposure to polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs) of chimney sweeps in Bavaria compared to a control group without occupational exposure. The PCDD/PCDF concentrations in the blood fat of 227 chimney sweeps were compared with the concentrations in samples from 60 controls. Using an internal standard containing 17 (13)C(12)-labeled PCDD/F congeners, the samples were cleaned up after fat elution using standard methods. The statistical analysis was adjusted to account for demographic differences, dietary habits, smoking status, and both occupational and nonoccupational contact with chlorinated hydrocarbons. Detailed information on the type of heating in the households swept, the length of time the chimney sweeps had carried out the profession (min 34, med 195, max 466 months) and the protective measures employed, were used to examine the influence of the working conditions specific to chimney sweeps on the internal PCDD/PCDF exposure. The correlation between blood-fat PCB concentrations as well as urinary chlorophenol concentrations and the exposure to PCDDs/PCDFs was evaluated. The sum of PCDD/PCDF components in chimney sweeps, expressed by International Toxic Equivalents (I-TEQ), was significantly increased compared to the control group (median: 26.36 versus 20.75 pg I-TEQ/g blood fat). For 37 chimney sweeps (16.3%) the sum of PCDDs/PCDFs exceeded the 95th percentile of the control group, i.e., 38.23 pg I-TEQ/g blood fat. Multiple regression analysis revealed that in addition to occupation, the variables age, district, and proximity to a waste incineration plant seem to have an effect on the internal PCDD/PCDF exposure. An additional influence on the internal exposure could not be determined for any of the special aspects of the work. We identified no high correlations between the concentrations of PCBs and chlorophenols and PCDDs/PCDFs. This study revealed significantly higher internal exposure to PCDDs/PCDFs in chimney sweeps than in the control group. The differences are small and within the range of the internal exposure to PCDDs/PCDFs in blood found in the general population in Germany since 1989. Further investigations in to PCDD/PCDF-related diseases in these study groups were not carried out.

Application of a purge and trap TDS-GC/MS procedure for the determination of emissions from flame retarded polymers.

Emissions of volatile organic compounds (VOCs) from different thermoplastic polymers used in electrotechnical applications were investigated using a purge and trap procedure that involved adsorption on Tenax GR. Results were compared to those for an operating TV set monitored in a test chamber. The analyses were in both cases carried out using thermodesorption gas chromatography with mass spectrometric detection (TDS-GC/MS). Substances identified were monomers, volatile additives, or related compounds. Special attention was given to the detection of halogenated compounds. Their origin was studied using reference samples and synthetic standards.

Analysis of flame retarded polymers and recycling materials.

Recycling activities on polymeric materials are increasing and becoming more and more important in recent years. For polymers containing no flame retardants, suitable recycling strategies already exist. In order to investigate the recyclability of flame retarded polymers that contain brominated flame retardants, a number of samples were analysed as received from a recycling company. Following the identification and sorting of the samples according to type of polymers and flame retardants, material recycling was tested for the flame retarded polymers identified to occur most frequently. The reactivity of the flame retardants during the recycling procedure was studied by analysing for brominated dioxins and furans. The results demonstrate that flame retarded polymers can be recycled under certain experimental conditions.

Investigation on organic pollutants from a domestic heating system using various solid biofuels.

Various herbaceous biofuels (straw, whole plant cereals and set aside hay) and spruce wood were tested for their potential to form PCDD/F, PCPh, PCBz and PAH during combustion. The trials were conducted in an automatically charged multi-fuel furnace for domestic applications (50 kWth). Both, flue gas and the different ash fractions were analysed. CO-emission results show, that combustion conditions were relatively uniform (mean CO-level: 200 mg/m3 at 13% O2 in flue gas). Likewise, the TOC- and PAH-emissions in the fuel gas remained constantly on a relatively low level. However, for the PCDD/F, PCPh and PCBz increased emissions were detected when herbacious fuels were applied. This may be attributed to their higher chlorine concentration and the high ash content, which is responsible for increased dust emissions during combustion. Similar observations were also found for the PCDD/F-concentrations in the ashes. Combustion chamber ashes usually showed a drastically reduced contamination with highly toxical compounds, compared to the ash fraction from the heat exchanger ash or to chimney soot.

Effects of the metal type and the roughness of the die wall on the expended work for tablet ejection.

The aim of the present work was to obtain an impression about the consequences for the tableting process when dies of different quality are used. Two hard metal dies and one die made from tool steel, each with a distinct roughness of the die wall, were compared by compacting dry-blended powder mixtures on an eccentric tablet press. The feasibility of the tableting process was assessed by quantifying the ejection force and the work expended by the lower punch during a first phase of the ejection process. With decreasing amounts of lubricant, abrupt permanent impacts were observed leading to conditions at which an ejection was no longer possible. This observation did not depend on the roughness of the die wall used or on the compaction pressure, but strongly depended on the metal type of the die used and on the tested formulation. For the tool steel no difference was found in this respect between the two tested formulations (0.5% versus 2% silica aerogel). In either case, a concentration of 0.3% magnesium stearate was sufficient; however, a concentration of 0.2% magnesium stearate was not sufficient. For both hard metal dies, concentrations of 0.3% (0.5% silica aerogel) and 0.5% magnesium stearate (2% silica aerogel) were definitely not sufficient. Within the ranges above a minimum lubrication, the ejection force and the ejection work increased with the degree of the die wall roughness on a scale comparable to that of the tested formulation factors. In particular, if changes of the die tooling are likely to occur in the life cycle of a product, it is highly recommended that the quality of the dies be considered in the development phase.

Psychopathological changes preceding motor symptoms in Huntington's disease: a report on four cases.

Neurodegenerative disorders often exhibit "classical" psychiatric symptoms as an initial presentation of the disease. Here we present four patients with different psychopathological abnormalities who were later diagnosed as having Huntington's disease. The range of symptoms covered affective and psychotic symptoms, antisocial behavior, cognitive problems reminiscent of dementia and suicidal idealisation. The pattern of progress of neuronal degeneration may be helpful in explaining the antecedent manifestation of psychiatric symptoms.

Repetitive transcranial magnetic stimulation (rTMS) in pharmacotherapy-refractory major depression: comparative study of fast, slow and sham rTMS.

In previous studies, fast repetitive transcranial magnetic stimulation (rTMS) with a frequency > 1 Hz demonstrated substantial antidepressant effects compared to sham rTMS. However, it is not clear whether fast rTMS is superior to slow rTMS (frequency < or = 1 Hz) which is safe at therapeutically promising higher intensities. The aim of this double-blind study was to compare the action of fast, slow and sham rTMS. Eighteen patients with pharmacotherapy-resistant major depression were randomized to receive fast (10 Hz), slow (0.3 Hz) or sham rTMS with 250 stimuli/day for 5 successive days. rTMS was applied at 90% motor threshold intensity to the left dorsolateral prefrontal cortex. Scores on the Hamilton Depression Rating Scale (HDRS), but not on the Montgomery-Asberg Depression Rating Scale (MADRS), showed a statistically significant time x group interaction with a reduction of 19% after slow rTMS. However, the effect was clinically marginal and not reflected by self-rating scores. Verbal memory and reaction performance were not impaired after rTMS, and there was even a statistically significant time x group interaction with improvement of verbal memory performance after fast rTMS. In conclusion, this study further supported the safety of rTMS but does not show any clinically meaningful antidepressant efficacy of rTMS at 250 daily stimuli over 5 days in pharmacotherapy-refractory major depression.

PCDD/F- and PAH-emission from house heating systems.

Combustion experiments were carried out in different house heating systems using various fuels. The emission samples and the chimney soot samples were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/F) and polycyclic-aromatic-hydrocarbons (PAH). The PCDD/F-concentrations in fluegases using untreated wood were in the range of 2-25 pg I-TE/m3. The combustion of paper, cartons, painted wood and wood with 2-5% PVC gave PCDD/F-concentrations from 38 to 952 pg I-TE/m3 and 380 to 2,240 ng I-TE/kg (chimney soot). The PAH-concentrations in flue gas were about 30 times higher using an old technology in relation to a new one.

Polyhalogenated dibenzo-p-dioxins and dibenzofurans in the exhaust air during textile processings.

5 textile finishing processes were investigated for polychlorinated dibenzo-p-dioxins/furans (PCDD/F), polybrominated dibenzo-p-dioxins/furans (PBDD/F) and mixed polychlorinated-brominated dibenzo-p-dioxins/furans (PBCDD/F). For the purpose of these investigations the complete balance--dioxins input from the raw textiles, output over the finished textiles and output through the air path--was done. In the exhaust air only small PXDD/F concentration were detected. The textiles contain before and after the process nearly the same PCDD/F-concentrations. The concentrations of PBCDD/F arises after the process. Only the chimney depositions contain higher PCDD/F-concentrations up to 1,806.1 ng I-TE/kg, PBDD/F-concentrations up to 1,572.6 ng/kg and PBCDD/F-concentrations up to 40,801.4 ng/kg.

Establishment of a simple cleanup procedure and bioassay for determining 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents of environmental samples.

The study was aimed at establishing a bioassay for the determination of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalents (TEQs) in environmental samples. Specifically, development of a rapid cleanup procedure adapted to the needs of the bioassay and simplification of the measurement of its endpoint, the induction of 7-ethoxyresorufin O-deethylase (EROD) in rat H4IIEC3/T hepatoma cells, were desired. The results indicate that a single "sandwich" column suffices to remove substances that may interfere with the bioassay from extracts of various environmental matrices such as sewage sludge, compost, soil, sediment, fly ash, tissue filter dust, and fire residue. The cumbersome conventional in vitro assay for EROD activity on cells exposed to the test material in culture plates could readily be replaced by a simple assay on intact cells grown and treated in 96-well microtiter plates. TEQ values obtained from the bioassays were consistently higher than those derived from chemical analysis of dibenzo-p-dioxins/furans and biphenyls by a factor of 1.5-3.0 depending on the matrix used. The results indicate that this bioassay, which combines a simple cleanup and a rapid procedure for measuring biological effects, offers a cost- and time-effective alternative to chemical analysis when screening large numbers of samples from complex environmental matrices.

[ISO 9001 conformity in research, teaching and rehabilitation]. / ISO 9001-Konformität in Forschung, Lehre und Rehabilitation.

Quality assurance, in particular in the areas of development and production of medical devices, is one of the tasks of biomedical engineering. The interdisciplinary working group "Functional Rehabilitation and Group Education, Vienna" is committed to the development and implementation of group education models on three levels: (1) direct education/instruction of patients with chronic diseases, (2) university research and teaching, and (3) development of technical aids for rehabilitation and the means for disseminating group education models in rehabilitation and therapy. Major aims were, by generating conformity with ISO 9001 standards, to achieve greater transparency and process optimization with very small resources in university (teaching, research, technical aids) and extra-university (rehabilitation) areas. A secondary aim was the establishment of interdisciplinary (clinical and biomedical) cooperation at university level. In all main areas (research, teaching and group education/instruction), ISO 9001-conformity was achieved by our activities on three methodological levels: (1) description and analysis of processes, (2) use of ISO 9001 standards for evaluating internal processes, and (3) optimization measures. The following article contains relevant elements of the quality manual and quality assurance system, and offers a typical example of innovative cooperation between medicine and medical engineering.

[Present status and future aspects of the respiratory pacemaker]. / Gegenwart und Zukunft des Atemschrittmachers.

Under certain conditions, phrenic pacing is a rare but most effective and attractive alternative for long-term ventilation. General indications concern diseases of the breathing center, for example Undine's disease (loss of CO2 sensitivity) in infants and high cervical spinal cord lesions in the level of C0 to C3. Despite of the advantage of physiologic respiration mode (no positive air pressure) compared to long-term ventilation, the phrenic pacemaker enables high life quality for the patients due to possibilities of closing of tracheostoma (Vienna system), an optimum in mobility and high cost effectiveness. International research and development in this area concerns 1. nerve transposition of an innervated nerve to a denervating phrenic nerve, 2. additional stimulation of thoracal muscles for inspiration, 3. additional stimulation of expiration, 4. endoscopic operative positioning of the electrodes, 5. development of a pacer with sensor input for an individual respiration rhythm (controlled by the vocal cord) and 6. development of a fully implantable system Improvements of the present pacemaker system may lead to enlargement of indications, for example use in patients with severe nocturnal arrhythmias in respiration.

Useful applications and limits of battery powered implants in functional electrical stimulations.

Battery powered stimulation implants have been well-known for a long time as heart pacemakers. In the last few years, fully implantable stimulators have been used in the field of functional electrical stimulation (FES) for applications like dynamic cardiomyoplasty and electro-stimulated graciloplasty for fecal incontinence. The error rate of battery powered implants is significantly smaller than that for conventional stimulator systems, and the quality of life for the patients is increased because the need for an external power and control unit is eliminated. The use of battery powered implants is limited by the complexity of the stimulation control strategies and the battery capacity. Therefore, applications like the stimulation of lower extremities for walking, cochlea stimulation, or direct muscle stimulation cannot be supported. The improvement of implantable batteries, microcontrollers, and ultralow power products is ongoing. In the future, battery powered implants will also meet the requirements of complex applications. Systems for restoration of hand and breathing functions after spinal cord injury can be the next field of use for battery powered implants. For these purposes, we developed a battery powered multichannel implant with a sufficient life span for phrenic pacing. The problems during development and the limits of this system are described in this paper.